Devices for generating a circulation of air in an oven are known in the art. See, for example, U.S. Pat. Nos. 4,071,739 to Jenn et al; 4,262,183 to Smith et al. These patents describe use of built-in electric fans to force circulation of air in ovens and thus cause a more efficient and rapid heat transfer to the food. Other patents describing air circulation in ovens are U.S. Pat. Nos. 3,991,737, 4,108,139 and 4,109,636.